How to get real HMR working with React-hot-loader

Hi!

Just starting a new app with this library. While it's smooth, it's maybe a bit TOO smooth as I had to jump through a lot of hoops to get real HMR working since you abstract away the babel config.

So here's what I did:

1. Since only presets starting with "babel-preset-" are automatically included, and I found no way to include them otherwise, the react-hot-loader preset is impossible to use. To fix this I created a new babel preset called `babel-preset-react-hot-loader` that just adds the babel stuff from React Hot Loader. Just install that and a big part of the work is done. You're welcome.

2. My `renderer/index.js` file looks like this, copied mostly from the `react-hot-loader` example:

```
import React from 'react'
import ReactDOM from 'react-dom'
import { AppContainer } from 'react-hot-loader'
import Root from './Root'

const render = Component => {
ReactDOM.render(


,
document.getElementById('app'),
)
}

render(Root)

// Webpack Hot Module Replacement API
if( module.hot ) {
module.hot.accept('./Root', () => { render(Root) })
}
```

Aaaaand it seems to work! State is now retained across hot replacements. I did not need to do the Webpack stuff that's mentioned in the `react-hot-loader` setup instructions, but maybe that will prove necessary in the future.

I think it's a bit misleading to claim that `electron-webpack` is HMR enabled, but then not provide any kind of documentation on how to use it. I had to make a new package just to add a babel preset to make it work with the most popular HMR tool for React. Out of the box state is not kept across hot replacements. Hope this helps someone!